1. Field of the Invention
This invention relates to a manufacturing method of a porous ceramic body having continuous three-dimensional through holes and which can be preferably used, for example, as a ceramic filter for filtrating non-metallic inclusion in a molten metal, and as a ceramic porous plug for floating up non-metallic inclusion in a molten metal by introducing a gaseous floating medium therefrom.
2. Description of the Prior Art
Recently, purification of a metal by using such a porous ceramic body is becoming more available. The features of a ceramic body necessary for the process depend on the shape of the through holes and the strength of the ceramic material from which the body is constructed.
It has been widely known that, as a manufacturing method, sinter ceramic materials have a larger diameter. A sintered body manufactured by this method, however, has not been suitable as regards the shape of the formed through holes because of the forming holes between each particle, and as regards the strength because of incomplete bonding of each particle.
Another manufacturing method to obtain a ceramic body includes pouring a ceramic slurry into a cavity having a laminated textile with a two dimensional net-like structure, which is dried and baked after taking out the cast body from the mold to decompose the textile. This is disclosed in a Japanese Patent Publication No.54-37617. Although, it is also difficult to obtain the through holes which communicate three-dimensionally with each other in the body after baking due to closing of the holes to be formed by the residue of the decomposing of the textile.
A purpose of this invention to provide a manufacturing method to obtain a ceramic body, in certainty, having through holes communicated three-dimensionally together and with high strength of the body itself.